Cal. Veh. Code § 35414

(a) Except where a load can be transported consistent with the limitations on vehicle and load length specified in other sections of this chapter, the limitations of this chapter as to length of vehicles do not apply when only poles, timbers, pipes, integral structural materials, or single unit component parts, including, but not limited to, missile components, aircraft assemblies, drilling equipment, and tanks not exceeding 80 feet in length are being transported upon any of the following:
1. (1) Upon a pole or pipe dolly or otherwise lawful trailer used as a pole or pipe dolly in connection with a motor vehicle.
2. (2) Upon a semitrailer, except for the limitations provided in Section 35410.
3. (3) Upon a semitrailer and a pole or pipe dolly used in connection with a truck tractor to haul flexible integral structural material.
(b) Poles and the tools and materials incidental to the work to be performed may be transported on a pole or pipe dolly or otherwise lawful semitrailer used as a pole or pipe dolly, transporting not more than three poles not exceeding 80 feet in length and when used by public utility companies or local public agencies engaged in the business of supplying electricity or telephone service, by the Department of Transportation, or by a licensed contractor in the performance of work for a utility, the department, or a local public agency, when such transportation is between a storage yard and job location where such tools and materials are to be used, in which event the limitations of this chapter as to length of vehicles and loads shall not apply.